1). Field of the Invention
Embodiments of this invention relate to the field of semiconductor chip processing and more particularly to an apparatus used in semiconductor chip processing.
2). Discussion of Related Art
Integrated circuits are formed on circular semiconductor wafers. The wafers are placed on sheets with adhesive on them and then sawed between the integrated circuits to form semiconductor chips also known as microelectronic dies.
The sawed wafers are then placed in a handling machine that includes a die ejector and a pick-and-place subsystem. The die ejector has an ejector head which separates each microelectronic die from the adhesive sheet which is then picked from the sheet and then placed on an integrated circuit board by the pick-and-place subsystem. Typically the ejector head has piercing pins which pierce the adhesive sheet and lift the microelectronic dies from the sheet so that they may be picked by the pick-and-place head.
One disadvantage of this system is that as microelectronic dies become thinner, the piercing ejector pins must eject the dies more slowly otherwise the thin, fragile dies will crack. Even slow moving pins cannot consistently operate to eject dies with thicknesses below 50 microns without the dies cracking. Another disadvantage is that even with die thicknesses for which piercing pins may be used, in order not to crack the dies, the pins must be slowed down such that the output of the microelectronic die handling system is reduced.